Some mobile electronic devices such as a mobile phone and a smartphone implement various functions related to a phone call by controlling its own device. For example, Japanese Laid-open Patent Publication No. 2000-209698 discloses a mobile set with a sound correction function (sound quality adjustment function) for correcting the frequency characteristic and the level of a sound output from a receiver or the like according to age-related auditory changes.
A phone call is a communication performed in real time with the counterpart on the phone call, and it is therefore preferred that keeping the counterpart waiting and accidentally ending the call or the like are prevented as much as possible. Because of this, it is very important for an operation screen related to the phone call to reduce an erroneous operation while allowing a quick operation. Therefore, the configuration of the operation screen related to the phone call is generally simple.